What is the octoshape app and what do I need to do about it

Simply do an Internet search on "Octoshape" and you should find a number of articles related to this. One of them indicates that Octoshape provides live and on-demand audio and video streaming ... and appears that the service is provided from Denmark. The service works on a Peer-to-Peer (P2P) concept and, most likely, got installed by clicking on a pop-up in a web browser.

Chances are that this app was developed earlier and was designed for 32-bit operating systems. The warning you are getting is telling you this, and at some future macOS update, it will not longer work on your Mac.

Octoshape appears to be a media / audio management software. You would have needed to download it at some point for some reason, or some other software may have downloaded it during installation. It belongs to Akamai, so if you have software from them it may have installed it.

https://www.akamai.com/

Apple is removing support 32 bit apps with the next version of macOS. Mojave still supports them.

You can choose to remove it, or see if there is an update for it to make it 64 bit compliant if you need to use it.

https://community.akamai.com/customers/s/article/Octoshape-Application-Client-for-Windows-OS-X-and-Linux?language=en_US